The long term objective of this project is the development and marketing of a patented-cardiovascular monitoring device thought to be an improvement over present invasive monitoring technology by simplifying the setup zeroing and calibration. The device will allow for accurate and uninterrupted invasive hemodynamic pressure monitoring from multiple sites. This setup will eliminate steps required to zero and level each transducer channel thereby allowing continuous and immediate monitoring crucial to safe patient care. Additionally, it will save money by decreasing the personnel-time and operating room and/or intensive care facility-time required for each zeroing and height levelling step. Specific aims for phase I are 1) to design and prototype an instrument which, in accordance with U.S. Patent #5,lO3,832, allows for automatic correction for hydrostatic height differences between patient and transducer while providing continuous zero pressure reference to the monitoring system, 2) to ideally configure and breadboard this system to be fully responsive over all physiologic ranges of pressure and required pressure response rates to allow for real-time zeroing and correction of sudden large changes in transducer height, 3) to prepare and develop a version of this prototype which can be easily manufactured, sterile- packaged, and marketed as an adaptable adjunct to existing systems.